Shredder-grinder machine having an improved rotor

ABSTRACT

A mobile chipper includes a housing which supports a feed roll positioned above a guide chute extending to a rotor having a series of axially spaced circular rotor plates rigidly secured to a driven rotor shaft. Each of the rotor plates is formed of a heavy gauge sheet metal and has a first segment which is integrally connected by a transverse portion to an axially offset second segment extending parallel to the first segment. A series of peripherally spaced shaft members extend axially through a segments of the rotor plates, and a plurality of hammer elements are mounted on each shaft member between the rotor plates for full 360* rotation. One of the hammer elements is positioned adjacent the first segment of each rotor plate in radial alignment with the second segment, and another hammer element is positioned adjacent the second segment of each rotor plate in radial alignment with the first segment. These hammer elements cooperate with other hammer elements so that the rotary paths of all of the hammer elements are continuous and uninterrupted across the width of the guide chute. Shredded material is discharged from the housing by the cooperation of a driven screw which extends to a centrifugal blower.

United States Patent 1 Scarbrough [1 3,724,767 [451 Apr. 3}, 1973 [54] SHREDDER-GRINDER MACHINE HAVING AN IMPROVED ROTOR [75] Inventor: John D. Sca'rbrough, Piqua, Ohio [73] Assignee: Pique Engineering Inc., Piqua, Ohio [22] Filed: Oct. 7, 1971 [21] Appl. No.: 187,395

[52] U.S. Cl ..241/186 R, 241/l01.7, 241/194 [51] Int. Cl. ..B02c 13/04, B02c 13/28 [58] Field of Search ..24l/l9l, 194,186 R, 186.2,

' Primary Examiner Donald G. Kelly Attorney-William R. Jacoxet al.

[57] ABSTRACT A mobile chipper includes a housing which supports a feed roll positioned above a guide chute extending to a rotor having a series of axially spaced circular rotor plates rigidly secured to a driven rotor shaft. Each of the rotor plates is formed of a heavy gauge sheet metal and has a first segment which is integrally connected by a transverse portion to an axially offset second segment extending parallel to the first segment. A series of peripherally spaced shaft members extend axially through a segments of the rotor plates, and a plurality of hammer elements are mounted on each shaft member between the rotor plates for full 360 rotation. One of the hammer elements is positioned adjacent the first segment of each rotor plate in radial alignment with the second segment, and another hammer element is positioned adjacent the second segment of each rotor plate in radial alignment with the first segment. These hammer elements cooperate with other hammer elements so that the rotary paths of all of the hammer elements are continuous and uninterrupted across the width of the guide chute. Shredded material is discharged from the housing by the cooperation of'a driven screw which extends to a centrifugal blower.

12 Claims, 4 Drawing Figures SHREDDER-GRINDER MACHINE HAVING AN IMPROVED ROTOR BACKGROUND OF THE INVENTION In a mobile chipper for shredding and grinding tree limbs, brush, small trees and other similar materials, commonly, the materials are fed generally radially into a power driven rotor which shreds the material into small pieces or chips. The chips are fed by a screw con- 1 veyor into a centrifugal blower which blows the chips through a discharge tube or duct into a receiving container. The rotor may be driven by a drive shaft connected to the power take-off of the vehicle used for towing the chipper, or may be independently driven by a gasoline engine. Preferably, the chipper includes a hammermill-type rotor having a series of peripherally spaced hammer elements or hammers which are supported for free rotation on axes extending parallel to the axis of the rotor.

It has been found desirable for each of the hammers to be supported for free 360 rotation so that each hammer is free to spin or rotate in the event the hammer engages an article which cannot be easily shreaded in one pass of the hammer. For example, US. Pat. Nos. 3,436,028, 3,510,075 and 3,044,719 each disclose a hammermill rotor having hammers supported for full 360 rotation.

It has also been found desirable to construct a hammermill rotor by mounting a plurality of axially spaced sheet metal plates on the rotor shaft and to mount the hammers on. peripherally spaced'shafts which extend axially through the plates to support the hammers for rotation between the plates, for example, as Shown in above US. Pat. No. 3,510,075. While this form of rotor can be economically constructed, the rotor plates produce corresponding dead areas between the paths of the hammers located on opposite sides of the rotor plates. When such a rotor is employed for chipping limbs, small trees and other pieces of wood, the dead areas between the paths of the hammers result in producing splinter-like pieces which are substantially longer than the small shredded pieces produced by the hammers. When the shreaded wood material is used as mulch, the long pieces of wood are undesirable since the pieces do-not quickly decay.

SUMMARY OF THE INVENTION The present invention is directed to an improved rotor for a hammermill-type chipper which is ideally suited for converting tree limbs, ground brush, small trees, corncobs, leaves, bark, sawmill offal, vines, stalks and other similar materials into small pieces of uniform size. The rotor not only provides for an economical construction but is also effective to position and support the hammer elements so that their paths are continuous and uninterrupted along the entire axial length of the rotor. As a result, the rotor of the invention significantly reduces the power required for driving the rotor.

"In accordance with a preferred embodiment of the invention, a chipper includes a housing which supports a driven feed roll for vertical movement above a feed chute and adjacent a generally cylindrical rotor. The rotor includes a series of axially spaced plates which are secured to a rotor shaft connected to the same drive means which drives the feed roll. Each of the rotor plates is constructed by forminga heavy gauge substantially circular sheet metal plate so that it has diametrically opposed segments which are axially offset in parallel relation.

A series of uniformly spaced shafts extend axially through the rotor plates, and a series of block-like hammer elements or hammers are mounted on each of the shafts between the rotor plates. One of the hammer 0 elements is positioned adjacent the inner surface of each segment of each rotor plate so that it is radially aligned with the diametrically opposed segment of the plate. Another series of hammer elements are spaced between the rotor plates so that the rotary path of each hammer element slightly overlaps the rotary path of another hammer element, thereby providing for continuous rotary hammer paths across the full width of the feed chute.

Other features and advantages of the invention will be apparent from the following description, the accompanying drawing and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a mobile chipper including a hammermill-type rotor constructed in accordance with the invention;

FIG. 2 is a fragmentary perspective view of the chipper shownin FIG. 1 and with portions removed to show internal construction;

FIG. 3 is an enlarged radial view of the rotor shown in FIG. 2; and

FIG 4 is a section taken generally on the line 4-4 of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT The chipper shown in FIG. 1 is ideally suited for shredding and grinding fibrous wood material such as tree limbs, ground brush and smalltrees, but may also be used for shredding and grinding many other materials such' as those mentioned above. In general, the chipper includes a rectangular trailer frame 10 which is supported by an axle (not shown) and a pair of wheels 12. A tow bar 13 extends from the frame 10 and includes a hitch 14 which is adapted to be coupled to a base housing 20 on a feed or guide chute 30 (FIG. 1)

forming an extension of the guide support surface 29. Preferably, the chute 30 is pivotable between a generally horizontal position (FIG. 1) and an upright collapsed position (not shown) when the chipper is being transported.

A driven feed roll 32 is positioned above the wall 29 and includes a shaft 33 on which is mounted a drum 34 supporting a plurality of outwardly projecting radial ribs 36. The feed roll 32 is supported for generally vertical movement above the wall 29 by a pair of pivotal arms (not shown) located outboard of the side walls 22 and 23 so that the feed roll 30 can accommodate materials of different thickness or sizes. The base housing 20 is enclosed by a cover housing 38 which is secured to the base housing 20 by a series of bolts (not shown).

In accordance with the present invention, a hammermill-type rotor 40 is positioned within the chamber 28 of the base housing 20 and includes a main rotor shaft 44 which is rotatably supported by a set of bearings 46 mounted on the side walls 22 and 23 of the base housing 20. The shaft 44 is connected by a multiple V-belt drive (not shown) to the output shaft of an internal combustion engine 50- (FIG. 1) which is mounted on the trailer frame directly in front of the housing 20. It is to be understood, however, that the shaft 44 may also be driven by other power means such as a drive shaft connected to the power take-off of a tractor or other vehicle used for towing the chipper.

Referring to FIGS. 3 and 4, a series of circular disc or plates 52 are mounted on the shaft 44 in uniform axially spaced relation and are rigidly secured to the shaft by corresponding welds 53. Each of the plates 52 includes a part-circular first segment 56 (FIG. 4) which is integrally connected to a diametrically opposed partcircular second segment 58 by a center section or portion 59 which extends transversely across the rotor shaft 44 at an acute angle relative to the axis of the rotor shaft. Thus as shown in FIG. 3, the segments 56 and 58 of each rotor plate 52 are positioned in axially offset parallel relation with each segment disposed in a radial plane with respect to the axis of the rotor shaft 44.

A series of four uniformly arranged holes 62 are formed within the segments 56 and 58 of each rotor plate 52, and the holes are aligned to receive corresponding rods or shafts 64 which extend axially through the segments of the rotor plates. A series of block-like hammer elements 65 are mounted on each of the axially extending shafts 64 between the rotor plate 52, and the shafts 64 are arranged with respect to the plate segments 56 and 58 (FIG. 4) so that each of the hammer elements 65 is free to rotate 360.

As shown in FIG. 3, a hammer element 65 is positioned adjacent the inner surface of each of the segments 56 and 58 of each rotor plate 52 and is located in radial alignment with the opposite segment of the rotor plate. Each of these hammer elements 65 is retained in position by a tubular spacer 68 which is mounted on the corresponding shaft 64 and which extends from the hammer element to the outer surface of the adjacent plate segment. Another series of hammer elements 65 are mounted on the two diametrically opposed shafts 64 which are located closest to the center portions 59 of the plates 52 and are positioned between the adjacent plate segments by sets of tubular spacers 69. Thus when the rotor 40 is being driven, the path of each hammer element 65 slightly overlaps the path of another'hammer element so that all of the hammer elements cooperate to produce continuous chipping and shredding along the entire axial length of the rotor 40 without any dead spaces between the paths of the hammer elements 65.

Referring to FIG. 2, an auger or a screw conveyor 75 is positioned within the chamber 27 of the base housing 20 and includes a shaft 76 which is also driven by the engine 50. The conveyor includes a tube 77 which is mounted on the shaft 76 and which supports a helical flight 79. The screw conveyor 75 extends continuously from the side wall 23 of the housing 20 through a circular opening formed within the wall 22 and into a boxlike housing portion 82 projecting from the housing 20. A circular flange 84 projects outwardly from the housing portion 82 and supports a rotatably positionable cylindrical blower housing 85 having an outlet duct 86.

A centrifugal impeller 88 is mounted on an end portion of the shaft 76 within the blower housing 85, and a telescoping discharge tube or duct 90 extends from the outlet duct 86 of the blower housing 85. A scoop-like deflector 92 is adjustably mounted on the upper end portion of the discharge duct 90 and provides for directing material blown through the duct 90 onto a pile or into a suitable container such as, for example, the bed of a trailer or truck to which the chipper is hitched. As shown in FIG. 1, a hopper 95 is mounted on top of the cover housing 38 and provides for feeding loose materials such as corncobs, leaves, etc. directly down into the rotor 40.

In operation, the materials to be shredded and pulverized are fed either into the hopper 95 or onto the guide chute 30 and wall 29 under the driven feed roll 30. The material is progressively fed by the feed roll generally radially into the driven rotor 40 so that the hammer elements 65 engage the material and shear or shred it into small fragments or pieces. The pieces are delivered by the rotor 40 to the screw conveyor 75 which feeds the pieces into the centrifugal blower impeller 88 for discharge through the duct 90.

As mentioned above, the construction of the rotor 40 is especially effective for reducing wood fibrous material to uniformly small or fine chips and for eliminating the formation of long splinter-like pieces of wood. That is, the formation of the rotor plates 52 from sheet metal plate to produce the axially offset segments 56 and 58 provides for a simple and economical rotor construction and, in addition, provides for locating and arranging the hammer elements 65 so that their corresponding rotary paths are continuous across the full width of the base housing 20 and along the full length of the feed roll 30. Furthermore, the construction of the rotor 40 minimized the power required for driving the rotor, especially when shredding fibrous wood material into small pieces.

The substantial spacing between the rotor plates 52 also provides for a generally open rotor which is desirable when shredding fibrous wood material to prevent clogging of the rotor. In addition, the circular configuration of the rotor plates 52 assures that the material is not fed beyond the outer portions of the outwardly projecting hammer element 65, thereby always assuring that each of the hammer elements is free to spin or rotate on its corresponding support shaft 64 when it engages an unusually tough material.

While the form of chipping and shredding apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope and spirit of the invention.

The invention having been described, the following is claimed:

1. An improved hammermill rotor adapted for use on a chipping and shredding machine, comprising a main support shaft, a plurality of plate members mounted on said shaft in axially spaced relation, each said plate member having a substantially uniform thickness and including first and second portions disposed in axially offset relation, a plurality of peripherally spaced shaft members extending axially through said offset portions of said plate members, a plurality'of hammer elements supported by said shaft members for freely rotating movement between said platemembers, and at least some of said hammer elements are located adjacent said first portions of said plate members and are generally radially aligned with said second portions of the corresponding said plate members.

2. A rotor as defined in claim 1 wherein said offset first and second portions of each said plate member are integrally connected by an intermediate portion which extends transversely of said shaft and forms an acute angle therewith.

3. A rotor as defined in claim 1 wherein at least some of said hammer elements are located adjacent the corresponding said second portions of said plate members and are generally radially aligned with said first portions of the corresponding said plate members.

4. A rotor as defined in claim 1 wherein each of said plate members including said offset portions is circular in configuration.

5. A 'rotor as defined in claim 1 wherein said first and secondportions of each said plate member comprise segments of said plate member. I

6. A rotor as defined in claim 5 wherein said offset segments of each said plate member are disposed in diametrically opposed relation.

*7. A rotor as defined in claim 1 wherein said shaft members are arranged relative to said offset portions of said plate members to provide for full 360 rotary movement of the adjacent said hammer elements.

8. An improved hammermill rotor adapted for use on a chipping and shredding machine, comprising a main support shaft, a plurality of sheet metal plates mounted on said shaft in axially spaced relation,each said plate including generally planar and radially extending first and second segments disposed in axially offset relation,

a pluralityof peripherally spaced shaft members ex-- tending through saidsegments of said plates parallel to said main support shaft, a plurality of hammers supported by said shaft members for freely swinging movement between said plates, and one of said hammers being located adjacent each said segment of each said plate and generally radially aligned with the other said segment of the corresponding said plate.

9. A rotor as defined in claim 8 wherein said first and second segments of each said plate are disposed in diametrically opposed relation, and said shaft members are arranged relative to said segments to provide for full 360 rotation of each said hammer.

10. A rotor as defined in claim 8 wherein some of said hammers are spaced between said segments of said plates and cooperate with said hammers adjacent said segments of said plates to provide a continuous array of hammer paths along the length of said rotor.

11. In apparatus for shredding materials such as tree limbs. brush and the like, and including a housing, a comminuting rotor supported for rotation within said housing means for directing material generally radially into sai rotor, means for discharging shredded material from said rotor, and means for driving said rotor, the improvement wherein said rotor comprises a plurality of axially spaced plates each having a uniform thickness, each said plate includes generally radially extending first and second portions disposed in axially offset parallel relation, a plurality of peripherally spaced shaft members extending through said offset portions of said plates, a plurality of hammers supported by said shaft members for freely swinging movement between said plates, at least some of said hammers being located adjacent said first portions of said plates in substantial radial alignment with said second portions, and at least some of said hammers being located adjacent said second portions of said plates in substantial radial alignment with said first portions.

12. Apparatus as defined inclaim 11 wherein said offset first and second portions of each said plate are diametrically opposed and are integrally connected by an intermediate portion which is inclined relative to said first and second portions.

s eward 

1. An improved hammermill rotor adapted for use on a chipping and shredding machine, comprising a main support shaft, a plurality of plate members mounted on said shaft in axially spaced relation, each said plate member having a substantially uniform thickness and including first and second portions disposed in axially offset relation, a plurality of peripherally spaced shaft members extending axially through said offset portions of said plate members, a plurality of hammer elements supported by said shaft members for freely rotating movement between said plate members, and at least some of said hammer elements are located adjacent said first portions of said plate members and are generally radially aligned with said second portions of the corresponding said plate members.
 2. A rotor as defined in claim 1 wherein said offset first and second portions of each said plate member are integrally connected by an intermediate portion which extends transversely of said shaft and forms an acute angle therewith.
 3. A rotor as defined in claim 1 wherein at least some of said hammer elements are located adjacent the corresponding said second portions of said plate members and are generally radially aligned with said first portions of the corresponding said plate members.
 4. A rotor as defined in claim 1 wherein each of said plate members including said offset portions is circular in configuration.
 5. A rotor as defined in claim 1 wherein said first and second portions of each said plate member comprise segments of said plate member.
 6. A rotor as defined in claim 5 wherein said offset segments of each said plate member are disposed in diametrically opposed relation.
 7. A rotor as defined in claim 1 wherein said shaft members are arranged relative to said offset portions of said plate members to provide for full 360* rotary movement of the adjacent said hammer elements.
 8. An improved hammermill rotor adapted for use on a chipping and shredding machine, comprising a main support shaft, a plurality of sheet metal plates mounted on said shaft in axially spaced relation, each said plate including generally planar and radially extending first and second segments disposed in axially offset relation, a plurality of peripherally spaced shaft members extending through said segments of said plates parallel to said main support shaft, a plurality of hammers supported by said shaft members for freely swinging movement between said plates, and one of said hammers being located adjacent each said segment of each said plate and generally radially aligned with the other said segment of the corresponding said plate.
 9. A rotor as defined in claim 8 wherein said first and second segments of each said plate are disposed in diametrically opposed relation, and said shaft members are arranged relative to said segments to provide for full 360* rotation of each said hammer.
 10. A rotor as defined in claim 8 wherein some of said hammers are spaced between said segments of said plates and cooperate with said hammers adjacent said segments of said plates to provide a continuous array of hammer paths along the length of said rotor.
 11. In apparatus for shredding materials such as tree limbs, brush and the like, and including a housing, a comminuting rotor supported for rotation within said housing, means for directing material generally radially into said rotor, means for discharging shredded material from said rotor, and means for driving said rotor, the improvement wherein said rotor comprises a plurality of axially spaced plates each having a uniform thickness, each said plate includes generally radially extending first and second portions disposed in axially offset parallel relation, a plurality of peripherally spaced shaft members extending through said offset portions of said plates, a plurality of hammers supported by said shaft members for freely swinging movement between said plates, at least some of said hammers being located adjacent said first portions of said plates in substantial radial alignment with said second portions, and at least some of said hammers being located adjacent said second portions of said plates in substantial radial alignment with said first portions.
 12. Apparatus as defined in claim 11 wherein said offset first and second portions of each said plate are diametrically opposed and are integrally connected by an intermediate portion which is inclined relative to said first and second portions. 